Concrete building construction

ABSTRACT

Building a structure in accordance with the new system includes setting up a plurality of column forms anchored to a footing, pumping one floor-height&#39;&#39;s worth of cement slurry into the forms, casting a floor at the tops of these columns; after the cement has set, pumping another floor-height&#39;&#39;s worth of the cement slurry into the bottoms of the column forms to raise the building for receipt of another, lower floor, etc., until the building is complete.

United States Patent 1 [111 3,795,465 Burkland Mar. 5, 1974 [54] CONCRETE BUILDING CONSTRUCTION 3,201,502 8/1965 Pluckebaum 264/34 1 Inventor: Raymond Burkland, 27 State 31333 161132? $322fi;;:::1:;.;::1 6035 St., Trenton, NJ. 08608 FOREIGN PATENTS 0R APPLICATIONS [22] Sept 1972 619,048 3/1949 Great Britain 425/63 [21] Appl. No.: 286,742

Related U.S. Application Data Primary Examiner-J. Spencer Overholser Assistant Examiner.lohn S. Brown Attorney, Agent, or 'FirmCushman, Darby & Cushman [57] ABSTRACT Building a structure in accordance with the new systern includes setting up a plurality of column forms anchored to a footing, pumping one floor-heights'worth of cement slurry into the forms, casting a floor at the tops of these columns; after the cement has set, pumping another floor-heights worth of the cement slurry into the bottoms of the column forms to raise the building for receipt of another, lower floor, etc., until the building is complete.

9 Claims, 8 Drawing Figures F 7 11 II I\ 11 J PATENTEDMAR 5 I974 SHEET 1 0? Q INVENTOR ATTORNEYS PATENTEW 5 m4 SHEET 3 0F 4 0 0 W B M M W M ATTORNEYS SHEET 0F 4 PATENTED AR 51974 INVENTOR ATTORNEYS N m N concnnrn nurwmo cossrnucrion This is a division, of application Ser. No. 33,478, filed Apr. 30, 1970, now abandoned.

BACKGROUND OF THE INVENTION The term building is used generically herein to include habitable structures such as apartment buildings, office buildings, similar structures, silos, storage tanks, warehouses and other storage entities and similar structures.

Most multistory buildings are built from the bottom, up, by creating a firm foundation upon which successively higher floors are built one upon another starting with the first lowest floor. In such construction, the top floor and roof are the last to be constructed.

Although this form of construction is time-honored and seems most logical, it actually suffers from serious inherent deficiency. Because such buildings are growing at the top, the top is the area where much of the work must be performed. Thus forms must be moved up, concrete and other supplies must be lifted up, workers must climb up and down, all with increasing loss of time as the building grows taller. In fact, in tall buildings, workers may spend much of their time getting their equipment, constructional materials and themselves to and from the upper area of the building where their work is to be performed. Also because the building is being built from the bottom, elevator installation work which would ease transport problems cannot be pushed to completion until the building has been topped out.

In addition, the major cost of erecting a reinforced concrete building framework consists of setting up forms to receive poured concrete which upon hardening requires the removal of these forms to a higher floor where the same procedure is followed each time a floor is poured. This work is mostly hand performed resulting in time consuming and costly production.

The present invention provides ways and means for building multistory buildings frorn'the top, down, and also eliminates most of the labor involved in the repetitive forming practices now required by conventional concrete column and floor construction. Admittedly, others have proposed systems for building buildings from the top, down while jacking the building up by floors, but in each instance now known to the applicant the jacking is performed mechanically or hydraulically with fluid other than the column cement. For instance, the patent of Pluckebaum, 3,201,502, of Aug. 17, 1965 shows a from-the-top, -down, -jack-up building system. The provision for pouring one more floors-height of concrete columns is shown best in FIGS. 12 and I3; jacking is shown taking place in FIG. 6. The Pluckebaum columns incorporate reinforcing.

The patent of Lenahan, 2,322,855, issued June 29, 1943 shows use of a pumpable, settable concrete slurry as the hydraulic fluid for jacking up a member for the support of a concrete column which has not been formed as part of the jacking process. Moreover, once the cement has set once, the Lenahan method is complete.

SUMMARY OF THE INVENTION The invention provides ways and means for building a concrete column and floor building from the top, down while jacking the building successively higher using pressurized, wet concrete slurry of the growing building columns as the jacking agent. Periodically, growth of the columns is suspended as a next lower floor is cast and connected to the columns so that, as column growth is recommenced, the newest floor will rise with the rest of the building.

Each of the columns is grown in a vertically elongated mold anchored to the building footing and having a cross-sectional shape corresponding to the crosssectional shape of the column to be molded therein. The base of each column mold includes an orifice for injection of concrete slurry into the mold and shut-off valve and check valve means.

In the presently preferred embodiment, the molding units are set up in a configuration for molding the concrete columns of a building structure, and have control means for operating all of the column forms and concrete slurry injectors in a synchronous manner in effecting the vertical movement of the columns.

A formwork of wood or other suitable material is erected on an horizontal plane conforming to the top level area of the molding units, to provide a platform for workmen and essential equipment, and also to provide a base upon which each of the successive floors of the structure may be poured. After the columns are molded to a predetermined height the flow of concrete slurry is shut off and molding is then commenced of the first floor to be poured in the said formwork which will be the uppermost floor or roof of the building. While or after, it has hardened, it is permanently connected to the columns which are then raised to the next predetermined floor plane, by reactivating the extrusion process at the base of the columns, thereby upwardly withdrawing the hardened floor just completed from the formwork, and leaving the formwork in position for the molding of the next lower floor. The same procedure is followed in pouring the succeeding lower floors.

All the molding units preferably have control means for maintaining the concrete floors in a level attitude by provision of a valve to control the rate of flow or to shut off the flow of concrete slurry into the enclosure forming the bases of the columns.

In this embodiment the flow of wet concrete into the column forms is shut off by closing the valve, whereupon the wet concrete may be allowed to harden within the column form. At any time thereafter, with the valve and orifice opened, additional wet concrete may be forced, under pressure, into each column form and against the hardened bottom surface of the previously formed portion of the column and sufficient hydraulic pressure exerted by pumps communicated to the concrete slurry in the column forms to raise the previously formed and hardened columns. Upon discontinuing injection of concrete slurry, concrete is removed from the valve and orifice of the column form bases.

The flow of wet concrete into the referred to molding units may be continuous at a controlled rate which permits sufficient hardening of the concrete being forced out of the open upper end of the molding units for the columns thus exposed to be structurally self supporting.

The concrete floors of the building structure may be successively molded on the horizontal platform with means for attaching the floors to the columns. Slip forms may be connected to a selected floor or floors for forming other concrete components related to the building structure. The vertical rate of column formation can control and conform to the rate of formation of the slip formed concrete components. The molding unit may be modified to permit the formation, during the extrusion and molding process, of a hollow core inside the column being formed. Concrete floors may be connected at any pre-selected horizontal plane in the columns. The horizontal width and/or the cross sectional shape of the columns can be varied to conform to the desired width and shape of the base members.

The axis of the molding units can be turned in any desired direction for molding of monolithic or hollow columns or related structural shapes with the molded and hardened concrete being forced out of the open end by the hydraulic action of the injected wet concrete in a direction opposite to the axis of the base member.

In all of the embodiments of the invention, the molding units may contain means for introducing reinforcing strands into the wet concrete during the molding process for providing reinforcing material in the hardened concrete.

The side members of the hollow molding units may be removed and replaced with new members or may be detached from the base members and remain in juxta position with the hardened concrete last molded within them, in which case new hollow members of larger cross section, would then be attached to the base members and the columns formation could recommence with larger cross-sectional moldings thereby resulting.

The principles of the invention will be further hereinafter discussed with reference to the drawings wherein preferred embodiments are shown. The specifics illustrated in the drawings are intended to exemplify rather than limit, aspects of the invention as defined in the claims.

BRIEF DESCRIPTION OF THE DRAWINGS In the Drawings:

FIG. I is a diagrammatic side elevation view ofa multiple story building being built in accordance withe the principles of the invention;

FIG. 2 is a vertical, longitudinal cross-sectional view of one column form and'its surroundings illustrating the growing of one column in accordance with the principles of the invention;

FIG. 3 is a horizontal, transverse cross-sectional view along line 3-3 of FIG. 2;

FIG. 4 is a vertical, longitudinal sectional view on a larger scale of part of the base area of one column form;

FIG. 5 is a vertical, longitudinal sectional view on a larger scale of the area of connection of one building floor to one column;

FIG. 6 is a vertical, longitudinal sectional view on a larger scale of the upper end region of one column form where the hardened concrete column emerges from the column form;

FIG. 7 is a vertical, longitudinal sectional view of a column form for production of a column which increases in diameter as lower floors are poured;

FIG. 8 is a fragmentary longitudinal sectional view similar to FIG. 4, but of a modified embodiment.

DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS A multiple story building 10 being built in accordance with the principles of the present invention is shown diagrammatically in FIG. 1. In utilizing the new system, after the foundation 12 has been conventionally emplaced on the bearing earth 14 (using piling and equivalent constructional elements when needed), a plurality of upright tubular column forms 16 are set up, leveled and bolted to the foundation 12. The column forms extended upwardly about the distance equal to the intended vertical distance between floors of the building. At the horizontal plane of the tops of the column forms 16 a floor form 18 is constructed and conventionally supported with respect to the foundation 12, e.g., using a plurality of vertical supports 20.

The column forms 16 each include a base unit 22 whose details will be further explained below. Suffice it to write in this general discussion that the base units each include means 24 for introducing wet concrete slurry into the bottoms of the column forms and means 28 for introducing reinforcing into the bottoms of the column forms to be tensioned and fed into the growing columns 28. There are also generally depicted reservoirs 34) for feeding wet concrete slurry to high pressure, low column slurry pumps 32 for forcing wet concrete slurry through conduits 34 into the bases 22 of the column forms 16.

In the process of building the building 10, sufficient concrete is pumped into the column forms under pressure to create the first, uppermost floors worth of columns 28A. The pumping is preferably conducted at such a rate that, by the time the upper ends of the columns 28A emerge from the column forms they are hardened sufficiently to be self supporting. A first uppermost floor (or the roof) 36A is poured on the floor form 18 and connected to the hardened upper ends of the columns while still supported on the floor form 18. The floor 36A may be conventionally reinforced and be conventionally provided with openings for stair wells, elevator shafts and the like.

At the time the floor 36A is being connected to the tops of the columns 28A, growth of the columns is preferably temporarily suspended and appropriate parts of the supply, pumping and base units cleaned to prevent concrete setting in them.

When the floor 36A has hardened sufficiently to permit its being removed from the mold 118, growth of the columns 28 may be begun again. At about this stage, other laborers may begin performing their constructional tasks on the completed portion of the building. For instance they may install roofing 38. Others may begin installing such roof-top components as cooling system evaporators, elevator draw works, high pressure water pumping units, ventilators and the like. It is important to note that these installations may be conducted right near ground level.

The next steps in growth of the building 10 are to force sufficient wet concrete slurry into the bases of the column forms, while feeding reinforcing wire, to grow a second floors worth of columns 283, after which a second, lower floor 368 is poured. It should be noted that sufficient force must be applied to the wet concrete slurry to cause it to raise the building 10 by one storys height. In effect the column forms 16 constitute cylinders, the hardened concrete of the lower ends of the columns 28A constitute pistons and the wet concrete slurry constitutes a hydraulic fluid forcing the pistons upwardly in the cylinders, thus raising the previously constructed portion of the building.

In like manner, after connection of the floor 36B to the juncture area between the column portions 28A and 283 further constructural work may be initiated,

such as installation of exterior walls 40 using fixed staging 42 and conventional wall supports 44 for brick facing 46 (if that type of facing is desired). Then column growth may be recommenced to produce the column sections 28C for a yet lower story, pushingup the building one more story in the process, then casting another floor 36C on the floor form 18 and connecting it to the columns 28 at the junctures of the sections 288 and 28C. Due to the preferred-shape of the upwardly facing surfaces of the column form bases 22 there is formed at the top of each column section a portion which may be easily chipped out when the column section upper end emerges from the respective column form, to pro duce a circumferential notch 48 which provides a site for secure connection of a floor 36 to the column 28.

Details of one preferred column form and its surroundings are shown in more detail in FIGS. 2-6.

The column form 16 includes a vertical tubular shell so circumferentially welded at its lower end 52 to a horizontal base plate 54.. The base plate is bolted to the foundation 12 at 56. Where needed, grout 58 is laid on the foundation, leveled and allowed to harden at the 1 site of the base plate 54 in order to provide a firm, level support for the column form. The base unit 22 of the column form comprises a thick cylindrical precast concrete, steel or similarly strong member received in the shell so adjacent its lower end. the bottom of the base unit rests on the base plate 54, the outer peripheral surface 60 engages the inner peripheral surface of the shell 50 and the upper surface 62 is generally conical being concave upwardly and having a central axial depression 64. A conical steel stamping 66 having an axially short tubular sidewall 67 integrally extending upwardly at its outer periphery is received upon the surface 62 and has a central, downwardly extending tubular neck 68 extending into the depression 64. The member 66 is circumferentially welded to the shell 50 at 70.

The base unit 22 further includes a horizontal, cylindrical, diametrical passageway 72 whose upper extent at its longitudinal midpoint intersects the depression 64. A pipe 74 comprising an extension of the conduit 34 is snugly received in the passageway 72 and protrudes through diametrically spaced openings 76 in the shell One protruding end of the pipe 74 is capped with a threaded pipe cap 78, the opposite protruding end is connected to the remainder of the conduit 34 via a swivel joint 80 and check valve 82. At the location where the passageway 72 intersects the depression 64 a lateral opening 84 is formed in the pipe 74. An annular gasket 86 of resilient sealing material seals between the tubular neck 68 and the pipe 74 at the location of the lateral opening 84.

At a plurality of angularly spaced locations, stiffening ribs in the form of radiating steel plate webs 88 are welded to the exterior of the tubular shell 50 and to the base plate 54.

The base 22 is completed by a plurality, for instance 4, angularly spaced wire tensioning and guide units 26. In the preferred embodiment these are elbow-like tubular members having an upper, vertical end portion opening through the stamping 66 into the column forming space 90 and a lower, horizontal end portion opening outwardly through openings 92 in the shell 50. Preferably the bore 94 of the wire guides is constricted throughout at least a portion of the length thereof in order to tension wire downstream of the constriction,

' i.e., wire within the column forming space 90. The constriction provides a sufficient drag on the wire passing therethrough to. maintain a desired amount of tension on the wire within the column forming space, particularly in the portion thereof which contains cement which has not yet hardened. The wire supply system further includes an individual (reeled) supply of wire 28 outside the column form 12 for each tensioner and guide 26 and a roller 96 against which each supply of wire is guided for straightening and alignment as it passes between the coiled supply and-entrance to the respective unit 26,.

In operation, wet cement slurry is fed into the hopper 30 where it is drawn into the pump 32 and forced via the conduit 34 into the pipe '74 from where it exits through the opening 84 into the column forming space 90. When sufficient cement slurry has been thus introduced into the column forming space to raise the column 28 one storys height, pumping is discontinued, the valve 82 closes whereupon the pipe 74 may be rotated e.g., through 180 degrees at the swivel joint 80 to cut off communication between the pipe 74 and the column forming space 90. Then the pipe 74, conduit 34, valve 82, joint 20, pump 32 and hopper 30 may be rinsed out with water so cement slurry does not set in them. The cleanout procedure may, if necessary, include removal of the pipe cap '78, and disconnection of the pipe '74 from the valve 82 and joint 80.

Upon recommencing column formation, the hopper may be refilled with slurry, the pump activated and the .pipe 74 rotated so the opening 84 is once again in communication with the column forming space 90. Wet concrete slurry entering the column forming space acting against the now hardened lower end of the previously poured portion of the column, forces that column portion upwardly in the column form, making room for incoming wet concrete slurry.

Should the pump 32 fail during column formation operations, the check valve 82 will close to protect against loss of wet cement slurry from the column forming space 90. Then, as a further precaution, the pipe 74 may be rotated to close it off from the column forming space 90.

It should be noted that the provision of the presence of the sidewall 67 within the tubular shell 50 results in there being formed an annular layer of concrete 98 formed in a subsequent pour radially overlying the bulk of the column at that level formed in a previous pour. Accordingly, the layer 98, when it emerges upwardly from the column form is not as strong as the underlying concrete and may be relatively easily chipped out to provide a circumferential notch 48 in the column 28 to facilitate attachment of a floor 36 to the column. To accomplish this, column formation is continued until the band 98 is at the lower extent of the floor form 18. Column formation is then temporarily discontinued and the band 98 is chipped out. Then an annular insert 100 Some cement shrinks upon curing. in order to pre vent operation of this phenomenon from allowing wet cement slurry from shooting up between the column and the column form when column formation is recommenced, a circumferential friction gasket 106 may be provided at the upper end of each column form. In the instance depicted (H6. 6), the gasket 106 is in the form of a stack 1108 of beveled washers or an equivalent coil of beveled strip stock of resilient steel or the like captivated within a gland nut 110 threadably received on the upper end of the column form tubular shell 50. The inner peripheral corner edges U2 of the annuli or turns of the beveled stack 1108 bear against the outer periphery of the emerging column within thenut 110 and the outer edges lid of the stack 108 elements bear against the interior peripheral wall 116 of the nut 1110. Thus, prior to reinstitution of column formation, the nut ll may be wrenched down until the gasket l08-ll6 is slurry-tight. Adjustments may be made to the tightness as needed.

if desired the surfaces 118 and 120 of the column mold may be permanently coated with conventional concrete mold release assisting agents so that no difficulty is experienced getting the column moving up wardly upon initiation of column formation after a pause for floor formation. Such release agents may include somewhat resilient baked on Teflon polytetrafluoroethylene. Such coatings, especially on the surface H8 may compress slightly upon the application of hydraulic force of incoming water or wet slurry to shoehorn incoming slurry in between the coated surface 118 and the lower end of the hardened previously poured portion of the column. I

After the building has reached its desired number of stories and the lowermost sections of the columns have hardened, the hoppers 30, pumps 32, floor form 18, conduits 34, pipe 74, valves 82 and swivel joints 80 may be recovered for use on other jobs. The column forms 16 including the remainders of the bases 22 may be left in place. The reinforcing wires may be suitably clamped using conventional means at 122 and the remaining unused wire supplies cut and the guide rollers 96 also recovered.

A modification is shown in FIG. 7 which permits molding of columns which increase in cross section in several (e.g., three) steps proceeding from the top toward the bottom of the building. in essence this is ac-- complished by providing a plurality-of coaxial shells 50 each having a stamping 66 provided with at least one set of wire guides 26 (one set is shown for the narrowest shell, two for the intermediate shell and three radially spaced sets are shown for the broadest shell 50) and respective necks 6S. Cement is prepoured and hardened at 124, 126 to provide initial support for the structure of FlG. 7. The base unit 22 is formed by a plurality of radiating steel plate webs I128 which bear against the bottom of the outermost, lowermost stamping 66. The wire guides and necks are accessible between adjacent webs ll28 through slots 130 in the outermost shell 50.

Cement slurry is first fed through the neck tSfiA and wire is fed through the guide 26A. When the column is to be broadened, cement slurry is fed through the neck 68B and wire is fed through the guides 268. When the column is to be broadened a second time, cement slurry is fed through the neck 68C and wire is fed through the guides 26C. As each change is made, the

formerly used shell 50A or 508 travels up buoyed by the next segment of growth of the column. Both sides of the shell 50 may be coated with a resilient material to provide easier vertical upward movement. Some details not heretofore discussed in full are with the knowledge of artisans in the concrete building design and construction field. For instance, the concrete hoppers may be manually filled by shovel, wheelbarrow or hydraulic hose from a central supply, or hydraulic hoses may be used to deliver slurry to the conduit 34 from a centrally located hydraulic pump supplying one or more column forms. For the first pour to start the building the tensioning wires may be pulled up through the column forms and secured to cross bars resting on or temporarily secured to the tops of the column forms.

.The growth of columns is conducted at a sufficiently slow rate that the concrete slurry has hardened into set concrete by the time it emerges upwardly from the column forms. Governors, back pressure control devices or other conventional means may be used to coordinate all of the pumps 32 for all of the columns, for instance from a common monitoring and control panel. The system of the invention can be used to produce columns of normal diameter. For instance, the system may be used to produce a 10 story building having a total average weight upon completion of about 7,500,000 pounds carried upon 25 columns each 20 inches in diameter and formed (as are its floors) in accordance with the principles of the invention. Thus the total columnar cross-sectional area is 7,850 square inches resulting in a maximum column load of 955 pounds per square inch. High pressure, low volume, positive displacement pumps capable of meeting and exceeding that amount of loading are readily commercially available. One such pump bears the designation Hydropulse HLV. 3-3GPM--3000 PSIG and is manufactured by DeLaval Turbine Company, of Trenton, New Jersey. Where the volumetric pumping rate of such pump is greater than that needed, a bypass can be provided as should be apparent. One kind of steel cable or wire recommended to be used as the column reinforcing is 12 gauge welded fabric construction wire made of steel and a typical tensile force to be applied by each guide 26 to the wire being pulled therethrough is l4,000 pounds' Another preferred embodiment of the invention is depicted in H0. 8, which should be compared with FIG. 4 for differences. Corresponding elements are provided with the same numerals.

Basically, what is different about the embodiment of FIG. 8 is that:

l. The space under the stamping 66 is relatively open since no solid filler is present. The radiating webs 88 extend under the stamping to support the stamping 66 and the weight of the formed column. Access ports through the tubular form 50 beneath the stamping facilitate tensioning wire feed and clean out operations.

2. The guides 26 for the wires 28 are shown being straight rather than curved, and include threaded die caps 15?. for adjusting the amount of tension applied to the wires 28. v

3. The location of the back-pressure cut off valve 82 has been shifted to a tapered seat 154 in the tubular neck 68. The valve $2 includes a matching tapered plug 156 having a stop 1158 on its lower end to prevent its traveling up into the column when pressure from wet cement slurry being pumped into the column form lifts it off its seat.

4. There is a plug 16f) provided in a corresponding opening in the conical portion 62. If difficulty is experienced in getting a column moving upwardly again following a pause for floor formation, fluid (e.g., water) under high pressure may be pumped into the column forming space through the opening shown closed by the plug 160 in order to provide an initial lift off.

5. The embodiment of FIG. 8 also includes the circumferential friction gasket 106 of FIG. 6. Note that a pressure relief valve 164 is provided at the inner end of the pipe 74. Accordingly when pumping is discontinued, the pressure relief valve 78 is opened whereupon the valve 82 closes and the pipe 74 is cut off from communication with the column forming space 90. The the pipe 74, conduit 34, valve 82, pump 32 and hopper 30 may be rinsed out with water so cement slurry does not set in them. (As the pressure in pipe 74 is reduced the vertically downward thrust of the column 28 is transferred in whole or in part to the friction gasket 106 at the upper end of the shell 50.)

It should now be apparent that the concrete building construction as described herein above possesses each of the attributes set forth in the specification under the heading Summary of the Invention hereinbefore. Because the concrete building construction of the invention can be modified to some extent without departing fromthe principles of the invention as they have been outlined and explained in this specification, the present invention should be understood as encompassing all such modifications as are within the spirit and scope of the following claims.

What is claimed is:

1. Apparatus for building a multi-story building of concrete construction from the top, down, upon a foundation, comprising:

a one story, tubular column form having means thereon for securement thereof in an upright condition to the building foundation;

a pedestal base unit for said tubular column form including a cylindrical plug forming the bottom of the column form;

' said plug having means defining a centrally depressed conically curved upper surface;

wet cement slurry introduction conduit means extending through said base unit form exteriorly of said column form and opening upwardly centrally through said centrally depressed conically curved upper surface;

I said conduit means including valve means for terminating and initiating communication between the interior and exterior of the column form, whereby, when said valve is in an open condition, wet cement slurry may be introduced into the bottom of the column form.

2. The apparatus of claim ll, the base unit further comprising at least one combined wire guide and tensioning means, each including a tubular element having one end opening upwardly through said centrally depressed conically curved upper surface at a point radially displaced from centrally of said surface, and having another end communicated exteriorily of the column form for receiving a supply of wire;

said combined wire guide and tensioning means tubular element having a throughbore containing means defining a radially constriction for engaging and exerting a drag on wire passing therethrough from the supply of wire and into the column form to thereby tension the wire within the column form.

3. the apparatus of claim 1, further comprising:

a high pressure, low volume, positive displacement slurry pump;

means for supplying wet concrete slurry to said slurry pump and conduit means extending from the slurry pump to the said conduit means of said column form base unit for supplying wet concrete slurry thereto under pressure.

4. The apparatus of claim 3 further comprising:

a check valve interposed in the conduit means between the slurry pump and the interior of the column form for prevention of reverse flow of wet concrete slurry within the column form upon suspension of pumping action by said slurry pump.

5. The apparatus of claim 1 further comprising;

a horizontal floor form supported on the foundation at the level of the upper end of the column form;

means defining an opening through said floor form in vertical registry with the column form whereby each time one storys worth of column has been formed in the column form, a floor may be formed upon said floor form and connected to the column at the level where the column emerges upwardly from said column form.

6. The apparatus of claim 1 wherein the centrally depressed conically curved upper surface of the base unit plug is permanently coated with a mold release agent,

7. The apparatus of claim 6 wherein the mold release agent is polytetrafloroethylene.

8. The apparatus of claim 1 further comprising a radially expensible-contractile gasket provided on said tubular column form at the upper end thereof circumferentially engageable with the column form and the column emerging from the column form to prevent leakage of pressurized wet cement slurry from the column form upper end. I

9. The apparatus of claim 8 wherein the gasket comprises a stack of annular bevelled steel strips and a gland nut housing said strips, said gland nut being threadable upon the upper end of said column form for flattening said stack to radially expand said stack. 

1. Apparatus for building a multi-story building of concrete construction from the top, down, upon a foundation, comprising: a one story, tubular column form having means thereon for securement thereof in an upright condition to the building foundation; a pedestal base unit for said tubular column form including a cylindrical plug forming the bottom of the column form; said plug having means defining a centrally depressed conically curved upper surface; wet cement slurry introduction conduit means extending through said base unit form exteriorly of said column form and opening upwardly centrally through said centrally depressed conically curved upper surface; said conduit means including valve means for terminating and initiating communication between the interior and exterior of the column form, whereby, when said valve is in an open condition, wet cement slurry may be introduced into the bottom of the column form.
 2. The apparatus of claim 1, the base unit further comprising at least one combined wire guide and tensioning means, each including a tubular element having one end opening upwardly through said centrally depressed conically curved upper surface at a point radially displaced from centrally of said surface, and having another end communicated exteriorily of the column form for receiving a supply of wire; said combined wire guide and tensioning means tubular element having a throughbore containing means defining a radially constriction for engaging and exerting a drag on wire passing therethrough from the supply of wire and into the column form to thereby tension the wire within the column form.
 3. the apparatus of claim 1, further comprising: a high pressure, low volume, positive displacement slurry pump; means for supplying wet concrete slurry to said slurry pump and conduit means extending from the slurry pump to the said conduit means of said column form base unit for supplying wet concrete slurry thereto under pressure.
 4. The apparatus of claim 3 further comprising: a check valve interposed in the conduit means between the slurry pump and the interior of the column form for prevention of reverse flow of wet concrete slurry within the column form upon suspension of pumping action by said slurry pump.
 5. The apparatus of claim 1 further comprising: a horizontal floor form supported on the foundation at the level of the upper end of the column form; means defining an opening through said floor form in vertical registry with the column form whereby each time one story''s worth of column has been formed in the column form, a floor may be formed upon said floor form and connected to the column at the level where the column emerges upwardly from said column form.
 6. The apparatus of claim 1 wherein the centrally depressed conically curved upper surface of the base unit plug is permanently coated with a mold release agent.
 7. The apparatus of claim 6 wherein the mold release agent is polytetrafloroethylene.
 8. The apparatus of claim 1 further comprising a radially expensible-contractile gasket provided on said tubular column form at the upper end thereof circumferentially engageable with the column form and the column emerging from the column form to prevent leakage of pressurized wet cement slurry from the column form upper end.
 9. The apparatus of claim 8 wherein the gasket comprises a stack of annular bevelled steel strips and a gland nut housing said strips, said gland nut being threadable upon the upper end of said column form for flattening said stack to radially expand said stack. 